On 15th jan i had intercourse but within 24 hours i had an ipill.since few days i am experiencing severe nausea and dizziness and acidity problems.what can be the cause ?can i still be pregnant?the first day of my last period was 3rd jan.please help

Check a test: If you think you might be pregnant check then check a home pregnancy test. They are cheap, reliable and available at any pharmacy. Emergency contraception decreases the risk but does not guarantee success. Since sex was only a few days ago it is too early for a test to work and too early for pregnancy to be the cause of these symptoms